New Porsche 911 Turbo vs. Cobra Question

[Jimbocobra]

Car and Driver April 2010 just tested a Porsche 911 Turbo and got a 2.9 second 0-60 and a quarter mile at 11.0 @ 128. It "only" has 500 hp, less than many of the Cobras out there and they are not running 11.0's on street tires with air conditioning. The 911 weighs 3540 (about 1000 lbs more than the average Cobra) and has less power. How the heck do they do it?
I get the rear engine and AWD for traction, double clutch, electronic shift and launch control, but still...you'd think the laws of physics would start to exist - 1000 lbs and less power....

[Kit Cars Mexico]

That is pure Technology.
If we put the same tech to our cars, we will not have Cobras

[Tim Brewer]

Go test drive a Porsche Turbo and you'll be able to answer any questions you may have.

[Barnsnake]

I believe you answered your own question.
Four big sticky tires pulling, electronic assists, and micro-second shift times. It's doing nothing but accelerating at the maximum possible rate, while the Cobra is still trying to find traction in 3rd. The difference in 60ft. times would be enlightening. In addition, after 80 mph or so the Porsche has a significant aerodynamic advantage.

Jim

[Rick Parker]

There is a reason Porsche has won so many times In IMSA, Can Am, Camel GT, LeMans and many others and the initial description of the current road test just touched upon how they do it. And it's done with what I think is still a twin cam 3.8 (?) liter flat six. These things run REAL hard.

[undy]

A 600 hp Cobra is not a 600 hp Cobra, is not a 600 hp Cobra...

The major MFRs (including Porsche) measure flywheel hp waaaaaayy different then the engine builders we've known and grown to love do. Our guys "optimize" everthing possible, great flowing headers/exhaust, pretty much zilch on parasitic losses and other misc HP producing tweaking. It's all about the bragging rights... and sales. Athough their measurement is "corrected", it's not corrected to the extent that the major automotive manufacturers do. GM started it all off by complying with the new SAE J1349 rating system. Under the new, more stringent system rated HP has dropped a significant amount. I believe Porsche has switched over to a similar, if not the same rating system.

Case in point ... When my C6 Z06 was bone stock it put down 450 rwhp, SAE corrected. (pretty much the average rwhp for similar Z06s) At 505 MFR rated hp that equates to a 11% parasitic loss. That seems to be repeatable by the majority. It would appear that most Cobras suffer a 20% to 30% parasitic loss, with a few on either side of the percentages. In a lot of cases your "600 hp" Cobra will put down around 450 rwhp, with an average set of decent flowing headers/sidepipes.

So, along with better suspension, stickier tires, 4wd, electronic HP enabling nannies add an accurately rated hp engine to the mix. It's no wonder the Porsche has better stats.

[Tommy]

It's not possible to accurately calculate a car's rate of acceleration from its weight and a single horsepower number for several reasons. For one, the engine does not run only at the RPM at which the horsepower was measured. It may have much less torque and horsepower at RPM's above and below that cited. And as was mentioned earlier, friction and aerodynamic drag can also differ significantly from car to car. The bottom line is that you can't declare winners and losers from looking at a limited set of data. You've got to run them side by side to see who's fastest.

[Don]

For comparison purposes:

May Car & Driver:

** Porsche 911 GT3: 435 HP , 0-60 : 3.8sec, 1/4 mile 12.1 @ 118 mph: , power to weight ratio is 7.5 pounds per horsepower: $ 130,000

** Ferrari 599XX: 720 HP, 0-62( 100 km/h) : 2.9 sec, 1/4 mile 10.8, no speed given: , power to weight ratio is 4.7 pounds per horsepower: $1,500,000

[CBattaglia]

A worked 87' 911 turbo tried to over take me on an on ramp merging onto a highway. It was a mid 3rd gear punch for me and he did not get around me. I went just over the century mark before I backed off and gave him the "nice try" nod

I bumped into the guy at a car show a few weeks later. He said I got the best of him, but I am sure that on a track or from a stop I wouldnt stand a chance.

[D-CEL]

And in here lies the answer to the much asked, angrily debated, often pondered and posted Club Cobra question: "How much HP is enough for a Cobra?"

Answer: Enough to safely cover any a$$-bag with a million dollar prancing horse, uber-turbo'd super car.

We should all be proud, took them 40 years and at least $100K just to compete

Jason

[CHRIS DAMSCH]

The Porsche has to be one of the most well thought out cars. Those things handle like a dream, stop on a dime and are set up so almost any idiot can look like a hero.

They are a lot easier to drive fast. Years of perfecting the design.

All around great car, I wish I had one in the stable.

[TurboVenom]

Say it three times:
Turbo.
Turbo.
Turbo.
Now you know how the Porsche does it.

[David Biele]

I have a 1996 porsche tt (air cooled) and it is slightly modded and make around 580 hp. They just put the hp to the ground. There is nothing like it. The reason I am selling mine it you can be on the freeway with the ac on and listening to great tunes not know you are doing 110 mph. Unless you driven one you never know. I do not want a ticket.

David

[DMXF]

...and what do you know, the track and wheelbase of the 911 are very close to a Cobra.